定时器设定的疑问

static void _rt_timer_init(rt_timer_t timer,
void (timeout)(void parameter), void parameter,
rt_tick_t time, rt_uint8_t flag)
{
/ set flag */
timer->parent.flag = flag;

/* set deactivated */
timer->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
timer->timeout_func = timeout;
timer->parameter       = parameter;
timer->timeout_tick    = 0;
timer->init_tick     = time;
/* init timer list */
rt_list_init(&(timer->list));

}
在以上定时器初始化过程中，对定时器所作的设定，具体是在什么时候设定到处理器的相关控制寄存器的？